Drill bit packages and methods

ABSTRACT

A plastic canister for storing and shipping drill bits, especially roller cone drill bit, has a pin-holder built into the lid of the canister for ease of field dressing the bit. The lid and body of the container are slip fit to one another and indexed to each other for positive positioning in their relationship. Safety features include the use of a conductive plastic polymer, a non-rolling base, mating protrusions and recesses for stacking, recessed areas for strapping, and welded loop handles.

[0001] This application claims priority from U.S. provisionalapplication Ser. No. 60/218,304, filed Jul. 14, 2000, which is herebyincorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] The present invention relates to packaging, and particularly topackaging of roller cone drill bits for shipment and/or storage.

Background: Roller-Cone and Fixed-Cutter Bits

[0003] In contemporary drilling practice, there are two basic categoriesof rock drill bits: roller-cone bits and fixed cutter bits. Within eachof these classifications, a range of sizes and design configurations areavailable.

[0004] A general schematic of a conventional rotary cone bit is shown inFIG. 6. The most common roller cone bits 60 have three independentlyrotating “cones” 62 (which may or be not be precisely conical) fitted onthree bearings. The cones will have cutting elements 64 or “teeth”attached to, or integral with the cones. The bearings are mounted on“arms” 65 whose other ends are attached to the body of the bit. There isa threaded drill string connection 67, commonly referred to as the “pin”on the junction of the arms at the upper end of the bit. Generally atleast three jet nozzles 68 are present on the bit to direct the flow ofdrilling “mud” toward the hole bottom. These jets come in a variety ofsizes, which may be changed on the site if deemed necessary.

[0005] A general schematic of a conventional fixed cutter bit 70 isshown in FIG. 7. The most common fixed cutter bits have at one end asupporting structure referred to as the “bit head” 72. Wear-resistantcutting elements 73 are strategically located on the outer and lowersurfaces of the bit head, as well as a number of jet nozzles 74. Afurther example of this type of rock drill bit is disclosed in U.S. Pat.No. 5,033,559 by Fischer.

[0006] A drilling site will generally have a number of bits available,both to deal with normal wear and tear of the bits, and to accommodatevarious conditions in the hole. A new bit will receive a finalinspection to be sure that no part of it is damaged and to exchangenozzles if necessary.

Background: Bit Packaging

[0007] While a great deal of work has been put into developing thetechnology of the drill bits themselves, less work has gone into thetechnology of shipping and storing them. The bits used for drilling oiland gas wells are consumable items which must be shipped to locations inthe remotest parts of the world. Bit packaging must provide reasonableprotection of bits against rough handling and corrosion during transportand storage. Bit packaging may also be subjected to rough-and-readyhandling practices on the rig floor or elsewhere in the field.

[0008] There is also some difference between the shipping and storagerequirements of roller-cone and fixed-cutter bits, in that roller-conebits tend to have more of their mass concentrated away from the pin endof the bit, due to the large fraction of the bit's mass in the cones.Thus a roller cone bit is not very stable when balanced on its pin end,but is typically quite stable when allowed to rest with its pin upright.

[0009] Roller cone bits have normally been shipped in this stable pin-upposition. Small drill bits (e.g. 50-200 pounds in weight) have usuallybeen shipped in a simple box of heavyweight corrugated cardboard, asshown in FIG. 5. Since the bit containers are likely to encounter roughhandling in the field, the cardboard must be very heavy-duty, and theseboxes are surprisingly expensive (typically more than $50 each inwholesale quantities). Even so, these boxes are not very durable.

[0010] Fixed-cutter bits have been transported with a packaging approachas shown in FIG. 4. This is a much more elaborate design and is executedin a tough plastic. This design requires that the fixed bit has slots 44which are designed for make-up and break-out. A U-shaped packaging piece46 slides into the breakout slots. providing a secure seating for thebit. The assembled U-shaped piece and bit are then lowered into the mainportion of the package, utilizing posts 45 in the body and correspondingholes 47 in the U-shaped piece to provide an exact seating in thepackage. Unlike the cardboard boxes, the weight of the bit would notnecessarily rest on the bottom of the container, but the weight would betransmitted by the post into the sides of the container.

[0011] One constraint on packaging is that the overall length ofdifferent bit designs may be different, even for a given hole size. Avariety of bit designs are used to adapt to the various kinds of rockwhich must be penetrated; for example, the average hardness, peakhardness, abrasiveness, or shale content of the formation being drilledwill all affect the choice of bit. The size and angulation of the conesand the type and length of teeth chosen will affect the length of thebit which must fit into a package. On the other hand, the need to havepackages of varying lengths as well as breadth increases themanufacturing costs of bits.

[0012] To summarize, it is desirable that a package be sturdy andprovide a stable environment for transporting the bit, as well as beingas easy to handle as possible. Protection from the environment isdesirable, as are safety concerns which arise from the handling of theseawkward, often heavy pieces of equipment. At the same time, theeconomics of producing the packaging must be considered.

[0013] Rotational Molding

[0014] Rotational molding is an inexpensive way to form large, moldedplastic items. A hollow mold is created, then filled with a measuredamount of a plastic powder. The mold is heated, to cause the powder tofuse together on the mold, and rotated, to cause the plastic powder toprovide an even coverage. Once the desired surface is coated, the moldis cooled and the article removed.

[0015] Innovative Packaging and Methods for Drill Bits

[0016] The present application describes a new approach to packaging,transport and/or storage of drill bits. This new approach includes anumber of innovations which can be used separately, in combination, orin various subcombinations.

[0017] In at least some embodiments, a two-piece, cylindrical polymercontainer, formed by rotational molding, holds a roller cone in acones-down position. A cushion of foam in the bottom of the containerprovides cushioning and lateral stability to the bit, while the lidprovides a holder to stabilize the pin. The lid and body, which are slipfit to each other, are preferably held together by strapping, which ispreferably constrained within channels formed in the package.

[0018] In at least some embodiments, the package has a bottom end whichis shaped to avoid rolling during transport (e.g. square or hexagonal).Use of a conductive polymer minimizes static electricity on the rigfloor. Mating protrusions and indentations on the lid and bottom of thepackage help to stabilize the bit containers when stacked.

[0019] In at least some embodiments, unsafe handling practices arediscouraged by welded loop handles and the retention of strapping withingrooves in the package, which will be explained in more detail later.

[0020] The disclosed innovations, in various embodiments, provide one ormore of at least the following advantages:

[0021] durability,

[0022] relatively inexpensive to manufacture,

[0023] reusable,

[0024] one package can handle a range of bits of a given bore size;

[0025] promotes safe handling of packaged bits.

BRIEF DESCRIPTION OF THE DRAWING

[0026] The disclosed inventions will be described with reference to theaccompanying drawings, which show important sample embodiments of theinvention and which are incorporated in the specification hereof byreference, wherein:

[0027] FIGS. 1A-B show perspectives of the innovative container, firstwith the lid off, then with it on.

[0028] FIGS. 2A-B show the inside of the lid looking straight down intoit and a perspective, showing the pin holder.

[0029]FIG. 3 shows the bottom of the container.

[0030]FIG. 4 shows a prior art package in which fixed-cutter bits havebeen transported.

[0031]FIG. 5 shows a sample box of heavyweight corrugated cardboard inwhich small drill bits have usually been shipped in the past.

[0032]FIG. 6 shows a general schematic of a conventional rotary conebit.

[0033]FIG. 7 shows a general schematic of a conventional fixed cutterbit.

DETAILED DESCRIPTION OF THE PREFERERRED EMBODIMENTS

[0034] The accompanying drawings show important sample embodiments ofthe invention and are incorporated in the specification hereof byreference.

[0035] In an exemplary preferred embodiment, shown in FIGS. 1a-1 b, thecontainer 10 consists of a body 100 and lid 200, which together form agenerally cylindrical shape. The inside diameter of the lid 200 is veryslightly larger than the body 100, providing a slip fit between the two.The lid overlaps the body for at least several inches, providing a morehermetic seal. The base 110 of the body, unlike the rest of thecontainer, is not round, but has a shape, such as the square shown,which discourages rolling if the container falls on its side. Recessedchannels 108 in the lid and base, and reproduced in the upper portion ofthe body of the container, provide a secure routing for the strappingwhich will hold the lid on the container during shipping. Sturdy handles106 are offset from the strapping channels 108 to provide a means forhand or machine lifting. Finally, protrusions 204 in the lid of thecontainer are sized to fit inside a cavity in the base of the container,providing some locking together of containers when they are stacked.

[0036] In this sample embodiment, the body and lid are formed fromlow-density polyethylene, with glycerol monostearate (GMS) added toincrease the conductivity. The walls of the container body are in therange of 0.25″ to 0.375″ thick. A cushion of an elastomer foam isfastened in the bottom of the container and is generally several inchesthick.

[0037] When a roller cone drill bit is ready for shipment, it is placedcones-down inside the body of the container, with the cones resting onthe foam cushion. The lid slip-fits onto the top of the body, and isfastened to the body by strapping. Inside the lid, a pinholder sleeve210 secures the pin end of the bit from loose lateral movement. The coneend of the bit is laterally stabilized by the contact between the coneteeth and the cushion. When the bit is packaged, a desiccant isgenerally added to the package to absorb moisture and discouragecorrosion. This can be any number of commercially available desiccants.

[0038] Preferably the polymer lid is fastened to the body for shippingby strapping 120 only, and not by any other attachment mechanism. Thisis a safety feature, since strapping (unlike latches, fasteners, ormolded screw threads) is not likely to be partly fastened: usuallystrapping will be either intact or broken, and it is easy to see which.By contrast, it is possible for built-in latches to break, or for somefasteners to be lost, or for screw thread engagements to be leftuntightened. The currently preferred strapping is a steel strapping, theends of which are generally fastened together by a metal “staple”, whoseends are bent over. A nylon strapping can also be used to secure thelid.

[0039] When the packaged bit is to be prepared for use at a remotelocation, the preferred package can be turned upside down, the strappingcut, and the body of the container lifted off. The pinholder sleeve inthe lid stabilizes the bit in the cones-up position, providing a stableplatform so that nozzles can easily be changed out. Other “bit-dressing”operations, as well as inspection, can also be easily performed in thisposition.

[0040] In the presently preferred embodiment, a further feature has beenadded to the container to secure the lid after the strapping is removed.In this feature, two heavy-duty T-shaped rubber straps 130 are attachedto opposite sides of the lid, offset from the handles. Two generallyU-shaped metal catches 132 on the container itself mate with the strapsto hold the lid closed.

[0041] In an alternate class of embodiments, a temporary strapping, e.g.of nylon, can be included in the container for closing the lid after theinitial opening, but this is less preferable, since unattached items aremore easily lost.

[0042] Details of the Lid

[0043] The inside of lid 200 is seen in FIGS. 2A-B. The cylindrical pinholder 210 is seen in the perspective of FIG. 2B, but is seen only as athin circle in FIG. 2A. The construction of the lid requires somefurther explanation. Rotational molding is preferably used to form thebody and lid. Rotational molding is a very economical and reliableprocedure, but it is limited in the range of shapes which can be formed.The present inventors found that rotational molding could not easilymake a compact lid with a rigidly attached integral pinholder. In thepresently preferred embodiment, two pieces are cut out from a singlehollow molding, and then attached together to form the lid with integralpinholder. The first piece 220 forms the portion of the lid which isvisible when the lid is in place on the container, and has generallycylindrical sides and a circular top, with grooves and protrusionsformed into it. The second, inner piece 230 is seen in FIG. 2a as aflat-doughnut-shaped piece, from which rises the cylindrical pin holder.The inner and outer portions are preferably attached together withliquid-tight rivets 240, so that the closed container will havereasonably good environmental sealing. This combination provides astrong structure which uses only a single-layer shell for most of thelid area.

[0044] Details of the Body

[0045] In addition to the perspective of the container shown in FIGS.1A-1B, a bottom view of the body 100 of the container is shown in FIG.3. While the walls of the container body are generally cylindrical inshape, this is not the case with the angular base 110, which providesanti-rolling stability. The base is here shown as having a generallysquare shape, but can be hexagonal, triangular, or any other shape whichdiscourages rolling. The handles 106, offset from the strapping grooves,are clearly seen. These handles are very heavy-duty, and have a 90degree stop to prevent fingers being mashed between the handle and thewall of the container by heavy loads. The handles are attached to thecontainer by studs, which are molded into the container as it is formed.Additionally, the walls of the container are somewhat thicker from nearthe outer edges of the handles downward, in order to provide a flat areafor attachment of the handles.

[0046] In FIG. 3, the base of the body is all that is visible, sincethis base is somewhat larger than the rest of the body. In addition thegrooves which hold the strapping, a circular area 112 is indented intothe base. When a container is stacked on top of a similar container, theprotrusions 204 in the lid of the lower container will engage in thecircular indentation 112 of the upper container. This prevents slippagebetween the relatively slick surfaces of the two containers.

[0047] Safety Issues

[0048] Several features of the preferred embodiment are designed todiscourage unsafe handling practices. This is a particular challengewith bit sizes which have weights in the range from (e.g.) 30 to 300pounds. In this intermediate zone of weights, manual handling ispossible but workers are also likely to use lifting aids when available.This results in a challenge for bit package design: the package designshould facilitate manual handling, but not encourage the use of liftingequipment in an unsafe manner. The preferred embodiment contains anumber of innovations which address this concern.

[0049] For instance, the container with bit is preferably lifted, eithermanually or machine-assisted, using both handles. However, it has beenassumed that under working conditions, workers will inevitably try touse a quicker method, such as attaching a lifting hook to only onehandle, or worse, trying to use the strapping which holds the lid on asa lifting point.

[0050] To address the first of these lifting practices, the inventorstested a number of commercially available “heavy-duty” handles, whichuse an open loop of bent rod for the handle. These stock handles werestrong enough for normal manual handling, but if the container snaggedon other equipment while being machine lifted, one end of the loop canbe pulled out of its restraint, allowing the whole package to fall.Instead, the handles are specially made, with the ends of the loopwelded together. Even under much higher stress, these handles will notcome open. For instance, although the bit and container will generallyweigh little more than 300 pounds, each handle can handle at least 800pounds pressure without breaking. Additionally, a stop on the handlekeeps the loop from rotating more than about 90 degrees outward from thepackage. This provides a comfortable position for handling, but keepsfingers from being mashed between the handle and the container.

[0051] For the second of the bad lifting practices above, the fact thatthe strapping is recessed into grooves makes it much harder to simplyslip a lifting hook through the strapping. Since this strapping is notdesigned to take this abuse, making this practice more difficultimproves safety. The lip of the body contains indentations whichregister with corresponding shapes in the lid, to assure that the strapgrooves in the body will align with those in the lid.

[0052] Another safety feature is the use of a conductive polymermaterial. The use of a conductive material minimizes static electricity,and thus the risks of explosion or fire on the rig floor.

[0053] Other Advantages

[0054] This package is not only very durable, but also relativelyinexpensive to fabricate. The preferred package is durable enough thatit can be reused if desired. Additionally, this design provides areasonable range of tolerances as far as height of the bit is concerned.With a slip fitting lid, the lid does not need to be seated all the waydown on the body, so a single package size can hold most normal rollercone bits of a given bore size. If desired, the sides of the lid can bedesigned to extend to just above the handles, allowing even more leewayfor longer bits.

[0055] Example of Dimensions

[0056] At this time, the containers are being made in three sizes toaccommodate the varying sizes of drill bits. Dimensions of the middlesize container are given below as an example. This should not be takento be a limitation on what can be done.

[0057] Total weight—10 lbs.

[0058] Weight of lid—3 lbs.

[0059] Weight of base—7 lbs.

[0060] Overall height—17½″

[0061] Diameter—11″

[0062] Height of lid—4½″

[0063] Depth of groove on lid—¾″

[0064] Depth of groove in bottom—⅜″

[0065] Height of protrusions on lid—¼″

[0066] Modifications and Variations

[0067] As will be recognized by those skilled in the art, the innovativeconcepts described in the present application can be modified and variedover a tremendous range of applications, and accordingly the scope ofpatented subject matter is not limited by any of the specific exemplaryteachings given.

[0068] It is specifically contemplated that the disclosed inventions arenot limited to roller cone bits, but can also be applied to drag bits.It is also specifically contemplated that the disclosed packagingdevices and inventions are not limited to packaging of bits, but can beused for downhole motors, bent subs, workover tools, core bits, reamers,hole openers, or in other components motors, bent subs, or for othertools.

[0069] Further information on drill bits can be obtained from The RotaryDrilling Series, Unit I, Lesson 2: The Bit (fourth edition), publishedby the Petroleum Extension Service of The University of Texas at Austinin cooperation with the International Association of DrillingContractors, which is hereby incorporated by reference.

What is claimed is:
 1. A container for transportation and storage of adrill bit, said package comprising a lid, said lid having a sleeveprojecting downwardly from said lid and capable of enclosing andsupporting the pin end of a drill bit.
 2. The container of claim 1,wherein said container is designed to transport rotary cone drill bits.3. A container for transportation and storage of a drill bit, saidcontainer comprising a body and a lid, wherein said body and said lidare held closed solely by strapping.
 4. The container of claim 3,wherein said container is designed to transport rotary cone drill bits.5. A container for transportation and storage of a drill bit, saidpackage comprising recessed grooves which can hold strapping in properpositioning.
 6. The container of claim 5, wherein said container isdesigned to transport rotary cone drill bits.
 7. The container of claim5, further comprising strapping which runs in said recessed grooves ofsaid container.
 8. The container of claim 5, wherein said containercontains handles offset from said recessed grooves.
 9. A container fortransportation and storage of a drill bit, said container comprisinggrooves which extend across substantially all the top and on at least aportion of the sides of said container, said grooves containingstrapping which maintains said container in a closed position, saidgrooves making it very difficult to fasten a hook through said strappingfor mechanical handling of said container.
 10. The container of claim 9,wherein said container is designed to transport rotary cone drill bits.11. A container for transportation and storage of a drill bit, saidcontainer comprising a body having a generally cylindrical shape, around lid which fits over said body, said body and said lid havingindexation which determines said lid's orientation with respect to saidbody.
 12. The container of claim 11, wherein said container is designedto transport rotary cone drill bits.
 13. The container of claim 11,wherein said indexation comprises mating grooves in both said lid and atleast portions of said container.
 14. A container for transportation andstorage of a drill bit, said container comprising welded loop handleswhich are stronger than needed for manual handling.
 15. The container ofclaim 14, wherein said container is designed to transport rotary conedrill bits.
 16. The container of claim 14, wherein said loop handleshave 90 degree stops.
 17. The container of claim 14, wherein said loophandles remain intact when subject to weight which is greater than twicethe expected weight of said container and a bit.
 18. A container fortransportation and storage of a drill bit, wherein the lateralpositioning of the bit within said container is determined sole from apinholder sleeve and the relationship between the bit and a layer offoam in the bottom of said container.
 19. The container of claim 18,wherein said container is designed to transport rotary cone drill bits.20. The container of claim 18, wherein said pinholder sleeve is part ofa lid of said container.
 21. A container for transportation and storageof a drill bit, said container comprising a polymer body, wherein afirst section of said container is substantially cylindrical and asecond portion of said container has a shape which is not conducive torolling of said container.
 22. The container of claim 21, wherein saidpolymer is a conductive polymer.
 23. The container of claim 21, whereinsaid container is designed to transport rotary cone drill bits.
 24. Acontainer for transportation and storage of a drill bit, said containercomprising a body designed to hold a drill bit and a lid designed to fitonto said body, wherein said lid and said body have respectiveprotrusions and indentations which mate together when said containersare stacked.
 25. The container of claim 24, wherein said container isdesigned to transport rotary cone drill bits.
 26. A container fortransportation and storage of a drill bit, said container comprising apolymer body and a polymer lid, said lid having a pinholder sleeveattached to the underside of said polymer lid.
 27. The container ofclaim 26, wherein said container is designed to transport rotary conedrill bits.
 28. The container of claim 26, wherein said lid is atwo-piece lid held together with liquid-tight rivets.
 29. A containerfor transportation and storage of a drill bit, said container comprisinga body and a lid, said lid mating with and overlapping the side of saidbody.
 30. The container of claim 29, wherein said container is designedto transport rotary cone drill bits.
 31. A container for transportationand storage of a drill bit, said container containing a rubber strapwhich mates with a metal catch to provide temporary attachment of thelid and body of said container in the field.
 32. The container of claim31, wherein said container is designed to transport rotary cone drillbits.
 33. A container for transportation and storage of a drill bit,said container comprising a body and a lid which mates with said bodyalong an axis of said body, wherein said lid and said body may befastened together in an adjustable relationship along said axis of saidbit, whereby said container accommodates different bit lengths.
 34. Thecontainer of claim 33, wherein said container is designed to transportrotary cone drill bits.
 35. A system of containers for transportationand storage of drill bits, wherein one size of container fits all normalbits of multiple different bore sizes.
 36. The system of containers ofclaim 35, wherein said one size of container fits all normal bits of agiven pin size.
 37. A method of preparing a drill bit for use in thefield, comprising the steps of: inverting a container in which saiddrill bit is stored; removing a body of said container so that saiddrill bit remains pin-down in a pinholder which is part of a lid of saidcontainer.
 38. A method of preparing a drill bit for use, comprising thesteps of: cutting strapping to open a container in which said drill bitis stored, said container comprising a body and a lid; inspecting and/ordressing said drill bit; and resealing said lid and said body other thanwith said strapping material which was cut.
 39. The method of claim 38,wherein said lid and said body are resealed using a nylon strappingincluded with said container.
 40. The method of claim 38, wherein saidlid and said body are resealed using a rubber strap and a metal catch,one of which is on said lid and the other of which is on said body. 41.A method of manufacturing a container for the transportation of drillbits, said method comprising: rotationally molding a single hollowpiece; cutting said single hollow piece to form first and second lidpieces; fastening said first and second lid pieces together to make alid having a pinholder on the inside of said lid.